Ring expander



L. C. RATHBUN RING EXPANDER Filed Sept. '19, 1934 3mm Louis CCRa, 672521.72,

Dec. 3, 1935-.

HIRE

Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to improvements in ring expanders, and the object of my improvement is to provide particularly for the enlargement of finger or other rings, a device suitable for this 5 purpose which will preserve the circularity of the ring while expanding it in diameter.

Another object of my improvements is to include in the device a stepped plurality of seats of which any one may receive a ring to be ex 10 panded or diametrically enlarged and for convenience in applying the ring thereto quickly according selectively to its size.

Another object of my improvements is to shape the enlarging part of the device to be hollowed l5 suitably to receive a conical mandrel for adjustably fitting and movably receiving it while equally propelling the separated tongues of the device radially in expanding a ring mounted upon one of the annular seats.

Another object of my improvements is to supply means for extracting the mandrel easily and quickly after performing its function as associated with said seating device in expanding a ring thereon.

25 All of the above objects I have accomplished in actual reduction to practice by the devices which are illustrated in the accompanying drawing, in

- which Fig. 1 is an elevation of the adjustably connected ring-seating device and its mandrel extractor. Fig. 2 is an axial longitudinal section of the elements of said Fig. 1, and of a ring seated on the device under expansion, and showing a conical mandrel seated within said device preparatory to extraction by the use of the extrac- 35 tor. Fig. 3 is an elevation of the termination of the ring seating part of the device.

The numeral I denotes the knurled head of a ring-seating body which is elongated and generally of cylindrical shape, the interior of the head 40 being threaded at 6 to seat a removable screw shaft l0 having the handle cranks l l on its outer end. The central hollow of this body is preferably enlarged toward its other end conically as at for adjustably seating a fitting conical man- 45 drel 9 removably.

The device I, beginning with a shoulder on its head part, is divided longitudinally to its further end by a plurality of slits 3 into a like number of similar tongues, and the slits 3 as shown in Fig. 4

50 are preferably arranged to be equally spaced apart circumferentially, and while eight of these slits and tongues are shown, any other plurality or arrangement thereof may be employed as desired, although when these are relatively numer- 55 ous the circularity of a ring after expansion is better preserved and is thus substantially attained.

Though not absolutely necessary in seating a ring 8 to be expanded upon a conical arrangement and shaping of the terminations of the 5 tongues 2, the outer surface of this conical part is shaped in a progressively widened set of fiat annular steps 1 to seat the ring upon any one according to the interior diameter of the ring, easily and quickly where the set of steps are representative of standard ring sizes.

The tongues 2 are resilient members, and may be all spread apart simultaneously in expanding a ring 8 seated on a step thereof, and to spring back when the mandrel 9 is removed.

To seat the mandrel 9, the screw I0 is initially removed, the small end of the mandrel then introduced within the tongues 2, and the end of the head part I hammered against the mandrel to force the mandrel into the conical seat 5 thus spreading the tongues diametrically to expand the ring 8 evenly. This being effected, the screw I0 is introduced into the threaded seat 4 and turned by rotation of the cranks II to force its conic termination against the end of the mandrel, thus displacing the latter enough to easily slip out, when the tongues will resiliently contract and the ring may be removed.

This appliance is especially for use by jewelers or merchants, in enlarging finger rings, but obviously the device may be varied in dimensions or changed in its parts or elements to subserve the above purpose in enlarging other types of annular or hollow bodies without departing from my invention or from the protection of the following claims.

Particular attention is invited to the feature of this invention as shown in Fig. 2, where the end of the body I which receives hammer blows to force the tongues 1 over and apart along the inserted mandrel 9 is shaped annularly at la to receive such blows as an anvil and by having that end part of the body I with an outwardly offset hollow inner wall for a short distance surrounding the threaded seat for the screw In, so that when the screw is separated from said body and the anvil end of the body hammered in a direction lengthwise and towards the mandrel, said offset wall part is not deformed enough by blows to interfere with the introduction of the screw into the threads and in serving to propel the mandrel outwardly in releasing said tongues after the ring thereon has been expanded.

I claim:

1. In a device of the character described, a holl5 low body having a head portion with a termination of the hollow ofiset circularly outwardly to provide a concussion end to receive hammer blows, and said head portion having the wall of said hollow beyond said offset threaded, said body having a plurality of resilient tongues projecting away from said head in an annular arrangement and coned toward its other end to receive thereon a ring to be expanded, and a screw seated removably in the threaded part of said hollow, spaced from the offset part of the body, and movable to terminally engage and force out a mandrel inserted into the opposite part of the body within and to expand said tongues.

2. In a device of the character described, a hollow body having an annular anvil termination, and having a plurality of spaced circularly arranged resilient tongues to seat thereon a ring to be expanded, the hollow of said body within said tongues being coned, a conical mandrel adapted to fit said conical hollow adjustably when the said body is driven thereupon by hammer blows on its unconed end, and removable means insertable into said body and spaced from said anvil part when the ring has been expanded to press upon and loosen the mandrel for easy separation from said tongues.

3. In a device of the character described, a hollow body with annular anvil termination and having spaced resilient tongues at one end to receive thereon a ring to be expanded, means insertable within said tongues to propel them outwardly in expanding the ring circularly, said body having at the other end its hollow wall interiorly threaded, and a screw seated movably and removably in said threads, and spaced from said annular termination, to engage said inserted means to remove it from close engagement with said tongues to permit removal of the expanded ring. 4. A device of the character described, coniprising a hollow body with an annular termination and having a plurality of spaced circularly arranged resilient tongues to seat a ring removably thereon to be evenly expanded circularly, the hollow being shaped within said tongues conically and the external terminations of the tongues being coned in their circular arrangement, a conical mandrel insertable within said conical hollow permitting the hollow body to be forced over the mandrel to expand said tongues in expanding the ring to a desired changed diameter, and a screw with a crank handle and insertable into the hollow of said body spaced from its annular termia nation, and removably engaging it adjustably to force out the mandrel from within said tongues.

LOUIS C. RATHBUN. 

